Mahogany growth and mortality and the relation of growth to site characteristics in a natural forest in Quintana Roo, Mexico

The management of mahogany (Swietenia macrophylla King) in the Yucatan peninsula of Mexico is based on the assumption that diameter at breast height (dbh) growth averages 0.73 cm yr−1 so mahogany will reach a harvestable dbh of 55 cm in 75 years. In 2002, transects were established in the forested area of Laguna Kaná in Quintana Roo, Mexico. All mahogany with a dbh ≥ 10.0 cm were measured and marked. In 2008/2009, the trees were remeasured, and tree, soil, and site characteristics and competition around each tree were recorded. Of the 499 trees studied, average dbh growth of surviving trees was 0.22 cm yr−1, far below the rate assumed by managers. Only 21 trees grew 0.73 cm yr−1 or more. Dbh growth was significantly correlated to initial dbh and the percentage of the soil that was Box lu'um, varied significantly among soil types and colors and was negatively correlated to stoniness. Growth was not significantly influenced by crown radius, basal area of competition, crown growing space, topographic position, microrelief, and soil depth (for soils 30 cm in depth or less). Mortality averaged 1% per year and was not related to initial dbh or initial commercial height. Forest management in Quintana Roo requires new science-based practices that increase the growth of standing trees and that ensure the establishment and continued recruitment of mahogany reproduction eng